Terbium

Terbium Element Properties

f64
Gd
Gadolinium
f65
Tb
Terbium
f66
Dy
Dysprosium
General
NameTerbium
SymbolTb
Number65
Group NumberNA
GroupRare Earth, Lanthanides
Blockf
Density8.27 g/cm3
Atomic Weight158.9254 g/mol
Atomic Volume19.2 cm3/mol
Discover1843


States
StateSolid
Melting Point1629 K
Boiling Point3503 K
Triple PointNil
Critical PointNil
Heat of Fusion10.15 kJ/mol
Heat of Vaporization293 kJ/mol


Energies
First Ionization Energy564.7 kJ/mole
Second Ionization Energy1112 kJ/mole
Third Ionization Energy2114 kJ/mole
Electronegativity1.21
Electron Affinity50 kJ/mole
Specific Heat0.18 J/gK
Heat Atomization389 kJ/mole atoms


Oxidation and Electrons
Shells2,8,18,27,8,2
Electron Configuration[Xe] 4f9 6s2
Minimum Oxidation Number0
Maximum Oxidation Number4
Minimum Common Oxidation Number0
Maximum Common Oxidation Number3


Appearance and Characteristics
Crystal Structurehexagonal
Characteristicssoft
Colorsilvery-white
Usesalloys
HardnessNil
ToxicityNone


Reactions
Reaction with Airvigorous, =>Tb4O7 (approx.)
Reaction with 6M HClmild, =>H2, TbCl3
Reaction with 15M HNO3mild, =>Tb(NO3)3
Reaction with 6M NaOHNone


Other Forms
Number of Isotopes1
HydrideTbH2 TbH3
OxideTbO2 Tb4O7
ChlorideTbCl3


Radius
Atomic Radius177 pm
Ionic Radius (1+ ion)Nil
Ionic Radius (1- ion)Nil
Ionic Radius (2+ ion)Nil
Ionic Radius (2- ion)Nil
Ionic Radius (3+ ion)106.3 pm


Conductivity
Thermal Conductivity11.1 J/m-sec-deg
Electrical Conductivity8.8 1/mohm-cm
Polarizability25.5 A3


Abundance
SourceMonazite(phosphate),bastnaesite
Relation Abundance Solar System-1.220 log
Abundance Earth's Crust0 log


f64
Gd
Gadolinium
f65
Tb
Terbium
f66
Dy
Dysprosium